Influence of temperature, modified atmosphere packaging, and heat treatment on aroma compounds in broccoli

The aroma compounds in broccoli stored in different modified atmospheres were studied. The packaging materials used were oriented polypropylene (OPP), poly(vinyl chloride) (PVC), and low-density polyethylene (LDPE) containing an ethylene-absorbing sachet. All samples were stored for either 1 week at a constant temperature of 10 degrees C or for 3 days at 4 degrees C, followed by 4 days at 10 degrees C. The atmospheres that developed inside the packaging materials differed significantly. The broccoli samples were analyzed raw and after cooking, with regard to volatile compounds, using gas-phase (headspace) extraction followed by gas chromatography-mass spectrometry (GC-MS) and GC-olfactometry. Dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), hexanal, 3-cis-hexen-1-ol, nonanal, ethanol, and a group of thiocyanates were selected for a detailed study because these compounds cause off-odor and can be used as indicators of stress. Significant differences were found in the aroma profiles of the broccoli samples relative to the packaging materials used for storage. Storage in OPP (14% O(2), 10.5% CO(2)) resulted in most of the off-odors, while storage in LDPE (6% O(2), 7% CO(2)) and PVC (17.9% O(2), 4% CO(2)) was found to maintain the concentration of DMS, DMDS, and DMTS during storage. Heat treatment of the broccoli increased the content of aroma compounds as well as the number of compounds containing sulfur.     

Effective Nutrient Sources for Plant Growth on Bauxite Residue: II. Evaluating the Response to Inorganic Fertilizers

An integral part of managing dust emissions from bauxite residue storage areas in Western Australia is the establishment of native vegetation and dust control crops. Recent changes to local health department regulations preclude the routine use of poultry manure, the previous standard fertilizer for growing dust control crops on bauxite residue sand. This paper reports on a field evaluation of different forms of inorganic fertilizer, to assess their effectiveness as alternatives to poultry manure for supplying nutrients to dust control crops. We compared plant growth and nutrient uptake under different forms of nitrogen (N) and phosphorus (P) fertilizers with additional potassium (K) and trace elements. A diammonium phosphate (DAP) based fertilizer blend which supplied 270 kg N ha^?1 of N and 307.5 kg P ha^?1 was found to be more effective than a superphosphate based blend containing the same amounts of these nutrients. The DAP treatment did not respond to topdressing with different N fertilizers, but plant growth in the superphosphate treatment was responsive to topdressing with N. Of the three different nitrogenous fertilizers evaluated for topdressing the superphosphate treatment (ammonium sulphate, diammonium phosphate, and urea), the ammonium based fertilizers were most effective. The DAP blend was the most cost effective of all the fertilizers studied, costing only A$1070 ha^?1 compared with A$2473 ha^?1 for the superphosphate blend and A$1600 ha^?1 for poultry manure. We concluded that the DAP fertilizer blend could be used as an effective replacement for poultry manure for growing dust control crops on bauxite residue sand.     

(99m)Tc-DMSA absolute and relative renal uptake in cats: procedure and normal values

In this study we investigated the influence of technical factors (positioning, background (BG) correction and attenuation correction) on qualitative and quantitative (absolute (AU) and relative (RU) uptake) assessment of feline kidneys with (99m)technetium labelled dimercaptosuccinic acid ((99m)Tc-DMSA). Eleven healthy adult cats were included. Influence of BG and depth correction on quantitative assessment was evaluated. Depth correction was based on the geometric mean method (using dorsal and ventral images) and the use of two standards placed over each individual kidney. Visual evaluation showed superiority of dorsal and ventral over lateral positioning due to increased separation of the kidneys permitting region of interest (ROI) placement without overlap. No apparent influence of BG correction was found for RU. However, AU was systematically overestimated without BG correction. Depth correction did not seem to affect RU in most cases, however, in some cats the differences were not negligible. The values for AU without depth correction were lower compared to depth corrected values.     

Assessment and quantification of post-weaning multi-systemic wasting syndrome severity at farm level

Post-weaning multi-systemic wasting syndrome (PMWS) causes major economic losses for the English pig industry and severity of clinical signs and economic impact vary considerably between affected farms. We present here a novel approach to quantify severity of PMWS based on morbidity and mortality data and presence of porcine circovirus type 2 (PCV2). In 2008-2009, 147 pig farms across England, non-vaccinating for PCV2, were enrolled in a cross-sectional study. Factor analysis was used to generate variables representing biologically meaningful aspects of variation among qualitative and quantitative morbidity variables. Together with other known variables linked to PMWS, the resulting factors were included in a principal component analysis (PCA) to derive an algorithm for PMWS severity. Factor analysis resulted in two factors: Morbidity Factor 1 (MF1) representing mainly weaner and grower morbidity, and Morbidity Factor 2 (MF2) which mainly reflects variation in finisher morbidity. This indicates that farms either had high morbidity mainly in weaners/growers or mainly in finishers. Subsequent PCA resulted in the extraction of one component representing variation in MF1, post-weaning mortality and percentage of PCV2 PCR positive animals. Component scores were normalised to a value range from 0 to 10 and farms classified into: non or slightly affected farms with a score <4, moderately affected farms with scores 4-6.5 and highly affected farms with a score >6.5. The identified farm level PMWS severities will be used to identify risk factors related to these, to assess the efficacy of PCV2 vaccination and investigating the economic impact of potential control measures.     

Predicting fadeout versus persistence of paratuberculosis in a dairy cattle herd for management and control purposes: a modelling study

ABSTRACT: Epidemiological models enable to better understand the dynamics of infectious diseases and to assess ex-ante control strategies. For Mycobacterium avium subsp. paratuberculosis (Map), possible transmission routes have been described, but Map spread in a herd and the relative importance of the routes are currently insufficiently understood to prioritize control measures. We aim to predict early after Map introduction in a dairy cattle herd whether infection is likely to fade out or persist, when no control measures are implemented, using a modelling approach. Both vertical transmission and horizontal transmission via the ingestion of colostrum, milk, or faeces present in the contaminated environment were modelled. Calf-to-calf indirect transmission was possible. Six health states were represented: susceptible, transiently infectious, latently infected, subclinically infected, clinically affected, and resistant. The model was partially validated by comparing the simulated prevalence with field data. Housing facilities and contacts between animals were specifically considered for calves and heifers. After the introduction of one infected animal in a naive herd, fadeout occurred in 66% of the runs. When Map persisted, the prevalence of infected animals increased to 88% in 25 years. The two main transmission routes were via the farm's environment and in utero transmission. Calf-to-calf transmission was minor. Fadeout versus Map persistence could be differentiated with the number of clinically affected animals, which was rarely above one when fadeout occurred. Therefore, early detection of affected animals is crucial in preventing Map persistence in dairy herds.     

Chemical alterations induced by <Emphasis Type="Italic">Pycnoporus sanguineus</Emphasis>/<Emphasis Type="Italic">Aspergillus flavipes</Emphasis> co-cultures in wood from different tree species

Chemical alterations following inoculation of Acacia mearnsii, Eucalyptus dunnii, E. grandis, and E. macarthurii with a Pycnoporus sanguineus/Aspergillus flavipes co-culture were investigated. Several wood chemical parameters were measured using standard methods from the pulp and paper industry. The data were described and analyzed using univariate as well as multivariate statistical techniques. Boxplots and in particular biplots show clearly how the chemical composition of each tree species was differently affected by the co-culture. Lignin content was significantly decreased in A. mearnsii, while E. dunnii showed a decrease in cellulose content. The results, therefore, indicate that the manner in which wood is degraded by a specific fungal co-culture depends on the tree species involved. This phenomenon should be considered when selecting fungi for bio-pulping.     

Differences between µCT‐imaging and conventional CT for the diagnosis of possible diseases of the middle and inner cat ear

The aim of this study was to check the relevance of using in‐vivo micro computed tomography (µCT) for the diagnosis of possible diseases of the middle and inner ear of the cat. Therefore, on the one hand, differences of the detail detectability between the two imaging methods conventional computed tomography (cCT) and in‐vivo µCT were analyzed. Six healthy cat ears were dissected and scanned several times and the obtained images were compared with each other. On the other hand, histological slices of all ears were prepared and pictures of defined anatomical structures were taken and compared with the identical sectional plane of the µCT‐images. This way it was possible to evaluate the quality and clinical limitations of the in‐vivo µCT. The results show that an in‐vivo µCT is suitable to analyze even the smallest osseous structures, such as the semicircular ducts, the spiral osseous lamina or the ossicles whereas with the help of cCT it is not possible to identify such small osseous structures because of their blurred and less detailed representation. Delicate soft tissue structures as the membranous labyrinth including hearing and vestibular organ cannot be differentiated with as well in‐vivo µCT‐ as with cCT‐images. In‐vivo µCT represent a good possibility for more detailed diagnosis of extremely fine structures which cannot be detected with cCT. Histological slices can nonetheless not be replaced by in‐vivo µCT due to a too low spatial resolution and the limitations of the in‐vivo µCT with regard to the evaluation of soft tissue dense structures.     

Plasma and urine pharmacokinetics of intravenously administered flunixin in greyhound dogs

Medication control in greyhound racing requires information from administration studies that measure drug levels in the urine as well as plasma, with time points that extend into the terminal phase of excretion. To characterize the plasma and the urinary pharmacokinetics of flunixin and enable regulatory advice for greyhound racing in respect of both medication and residue control limits, flunixin meglumine was administered intravenously on one occasion to six different greyhounds at the label dose of 1 mg/kg and the levels of flunixin were measured in plasma for up to 96 hr and in urine for up to 120 hr. Using the standard methodology for medication control, the irrelevant plasma concentration was determined as 1 ng/ml and the irrelevant urine concentration was determined as 30 ng/ml. This information can be used by regulators to determine a screening limit, detection time and a residue limit. The greyhounds with the highest average urine pH had far greater flunixin exposure compared with the greyhounds that had the lowest. This is entirely consistent with the extent of ionization predicted by the Henderson–Hasselbalch equation. This variability in the urine pharmacokinetics reduces with time, and at 72 hr postadministration, in the terminal phase, the variability in urine and plasma flunixin concentrations are similar and should not affect medication control.